Pipe Fan, Ehaust Fan, Duct Fan manufacturer / supplier in China, offering Ventilation Multi-Speed Circulation Inline Duct Pipe Exhaust Fan (SFP-150), Metal Wall Fan 4′′ 120x38mm Quality Warranty 2 Years for Ventilation, 4′′ AC Fan with Metal Frame and Impellers 120x120X38mm 220VAC and so on.